ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCC%28C%28%3DO%29C1%3DCC2%3DC%28C%3DC1%29OCO2%29N3CCCC3/file?format=sdf&get3d=True  -- CCCC%28C%28%3DO%29C1%3DCC2%3DC%28C%3DC1%29OCO2%29N3CCCC3 could not be loaded.